1. Field of the Invention
The present invention relates to a method of producing a finite-element model of a unique body of shape and structure that are complex, as applies to certain bones of the human or animal body.
2. Brief Discussion of the Related Art
Using finite elements to model a body of complex shape is nowadays a proven technique. It is used for simulation to predict the behavior of a body, of an article, or of a member, . . . under certain loading conditions representative of those it will encounter either while in normal operation or use, or else in situations that are exceptional.
The fields of use for such simulation are very diverse, going from computer-assisted surgery (orthopedic operations for repairing disorders due to an accident or to disease, possibly accompanied by installing an implant), to preventative medicine (in particular predicting the behavior of a bone element that is subjected to osteoporosis), and also including studying and analyzing the behavior of the human or animal body when subjected to various normal or abnormal conditions such as impacts that result from car collisions or from practicing a sports activity, . . . .
A model is produced on the basis of measurements taken from the body that is to be modeled by means of X-rays, photography, palpation, tomography, . . . , the measurements being digitized or subjected to any equivalent technique serving to obtain data about the outer shape of the body and about its inner structure.
The predictive function of modeling is made more precise by using a greater number of elements and by using a meshing (subdivision into coupled-together finite elements) that is satisfactory in terms of the shape of each mesh.
Meshing a real body requires preparation time that increases with increasing complexity of the body and with increasing requirement for the model to be accurate. Furthermore, an accurate model also requires a large amount of processing time while it is “in operation”, i.e. computation time that is lengthy in order to obtain a realistic image of its behavior and of the way it deforms under such and such a mechanical load. Thus, the state of the art in this field comprises models that are produced to simulate behavior quickly but too crudely, or that are accurate but much too slow.
However, the need for personalized models of this type is both ever increasing and also ever more demanding in terms of response time. This applies in particular to the medical field and more particularly to the orthopedic field in which computer-assisted surgery is becoming ever more widespread. There is also an existing need in preventative medicine for simulating the behavior of a femur under such and such a stress and for deducing the degree of risk and in particular of breakage incurred by the subject.